M ad e in Ge rm any
© Gigahertz Solutions GmbH
The Landessanitätsdirektion Salzburg (Austrian health author-
ity) proposed already in 2002 to lower the present ”Salzburger
Vorsorgewert“ (precautionary value) to 1 µW/m² for indoor
situations.
Limiting values imposed by governments are mostly considerably
higher. There are indications of rethinking, though. The Internet
provides large collections of recommendations and data.
Note for users of cellular phones: Even below 0.01 µW/m² com-
munication is fully unimpaired.
Identification of the sources of pollution
After determination of the total exposure the next step is to find out
where the radiation enters the examined room. As a first step
eliminate sources from within the same room (e.g. cordless
phones, wireless routers, etc.) Once this is completed, the remain-
ing radiation will originate from outside. For remedial shielding it is
important to identify those areas of all walls (including doors, win-
dows and window frames!), of ceiling and floor, which are pene-
trated by the radiation. To do this one should not stand in the cen-
tre of the room, measuring in all directions from there, but monitor
the permeable areas with the antenna (LogPer) directed and posi-
tioned close to the wall/ceiling/floor
9
. The reason for this is that the
antenna lobe widens with increasing frequency. In addition reflec-
tions and cancellations inside rooms make it impossible to locate
the “leaks” accurately. See the illustrating sketch below!
Wand
Wall
Mur
Pared
antenna antenna
potentiell
durchlässiger
Bereich
no!
Potentiell durchlässiger Bereich
Potentially permeable Area
For the definition and installation of shielding measures as well as
surveying their effect, professional advice is recommendable.
Anyway, the area covered by shielding material should be much
larger than the leak itself.
Audio Frequency Analysis (HF35C / HF38B only)
Many different frequencies within the frequency band between
800 MHz and 2.5 GHz, are being used by many different services.
The audio analysis
10
of the modulated portion of the HF signal
helps to identify the source of a given HF radiation signal.
Sounds and signals are very difficult to describe in writing. The
best way to learn the signals is to approach known HF sources
very closely and listen to their specific signal patterns. Without
detailed knowledge, the characteristic signal patterns of the
following HF sources can be easily identified: 2.4 GHz telephones
9
Please note: In this position the readings on the LCD only indicate relative highs
and lows that cannot be interpreted in absolute terms.
10
Turn the attenuator knob for the audio analysis fully to the left („-„) before be-
ginning, as it might become very loud, when switching while monitoring a high
intensity radiation.
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